View source for 3-inch Mk.34 (76 mm)

[[File:3-inch Mk.34 (76 mm).jpg|thumb|x250px|'''{{PAGENAME}}''' on {{Specs-Link|us_destroyer_mitscher}}]]
== Description ==
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The '''3-inch/50 calibre Mark 34''' gun was developed by the US Navy during World War II as a response to the ineffectiveness of existing 20 mm and 40 mm anti-aircraft batteries against Japanese Kamikaze attacks. Designed as an upgrade of the 3"/50 calibre Mk. 22 gun, the Mk. 34 featured an autoloader that significantly improved its rate of fire, making it more effective against fast-moving aircraft. The gun entered service too late for use in World War Two, but it saw service from the late 1940s to the 1980s, replacing 40 mm Bofors on many US and allied ships. The Mark 34 was the single-mount variant, used notably on ships like [[USS Roanoke]] and other early post-WW2 vessels.

In-game, '''{{PAGENAME}}''' is an exceptionally effective anti-aircraft gun, owing to her rapid-fire {{Annotation|HE-VT|High-explosive variable time fuse}} rounds and a very good vertical guidance of +85°. She can also be used against surface targets with either HE or AP rounds, though the armour-piercing ammunition suffers from a very small explosive filler.

=== Vehicles equipped with this weapon ===
<!-- ''List out vehicles that are equipped with the weapon.'' -->

* {{Specs-Link|jp_escort_akebono_class}}
* {{Specs-Link|us_ashville_class}}
* {{Specs-Link|us_frigate_dealey}}
* {{Specs-Link|us_ashville_class_douglas}}
* {{Specs-Link|us_destroyer_mitscher}}
* {{Specs-Link|us_cruiser_worcester_class_roanoke}}

== General info ==
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Being a rapid-fire gun with an excellent choice of ammunition and good penetration characteristics, the 3-inch Mk. 34 can be used in a wide variety of roles. From dealing with aerial targets to countering coastal vessels and even breaching the [[ammo racks]] of destroyers, the gun performs well in every role. Its only downside is its relatively small calibre, which limits its damage potential against larger surface targets.

=== Available ammunition ===
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{{:{{PAGENAME}}/Ammunition|76 mm HC Mk.27, 76 mm APHE, 76 mm AA Mk.31}}

=== Comparison with analogues ===
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Typically, for post-WW2 guns, the 3-inch Mk. 34 features an excellent rate of fire and damage output. The only problematic round is the APHE, which has an unusually low explosive filler without any increase in penetration compared to guns such as the [[39-K (76 mm)|76 mm 39-K]].

==== HE ====
{{Naval 76mm HE}}

==== SAP/AP ====
{{Naval 76mm AP}}

== Usage in battles ==
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The 3-inch Mk. 34 is usually assigned to either the secondary or primary armament group. Vessels that have it in the secondary group will automatically engage enemy aircraft and surface combatants using AI gunners, but manual control can be taken over with the use of select secondary weapon control (default {{Key press|Alt|2}}). If the gun is in the primary group, it can be delegated to AI by switching to any other weapon group (weapon group switch, default {{Key press|Left Ctrl|E}}). This is important, as AI gunners will engage enemy vessels from as far as 4 kilometres away, which, combined with the {{Annotation|HE-VT|High-explosive variable time fuse}} rounds, can often be a lifesaver, destroying enemy aircraft long before they have an opportunity to drop bombs on your vessel.

The gun is also very effective against surface vessels, particularly motor torpedo boats, owing to her high rate of fire and good muzzle velocity, making it easy to correct aim on target, while the {{Annotation|HE|High-explosive}} rounds will effectively destroy them in a few hits. Against frigates and destroyers, a choice of {{Annotation|APHE|Armour-piercing high-explosive}} rounds might be preferable, especially when targeting [[ammo racks]].

=== Pros and cons ===
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'''Pros:'''
* High rate of fire
* Excellent vertical guidance
* Often available in a twin-mount
* Good muzzle velocity
* Access to a wide choice of rounds

'''Cons:'''
* Very low explosive filler of the APHE rounds, equivalent to only 63.7 grams TNT

== History ==
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The 3-inch Mk. 34 gun was developed by the United States Navy in response to Japanese Kamikaze attacks. Designed as an intermediate-calibre solution between the lighter 40 mm Bofors and the heavier 5-inch/38 (127 mm), the gun used a 76.2 mm, 50-calibre-long barrel with an electrically-driven autoloader. This allowed for a high rate of fire and tracking of fast-moving aircraft.

The Mk. 34's single mount was similar in size to the quad 40 mm Bofors, and despite the heavier mass, it was possible to replace Bofors on a one-for-three basis. Such a replacement proved beneficial in testing, where it was found that a single 3"/50 was as effective as two 40 mm quad guns.

The initial prototype was ready by 1 September 1945, but with the end of the war, deployment was delayed until 1948. It became the weapon of choice on numerous US and allied ships from the late 1940s through to the 1980s. However, the history of the gun dates back to 1915, when the initial versions were introduced as dual-purpose weapons, undergoing modernisations and redesigns over the decades, culminating in the Mk. 34, which was the last significant upgrade for the gun.

== Media ==
''Excellent additions to the article would be video guides, screenshots from the game, and photos.''

== See also ==
''Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:''
* ''reference to the article about the variant of the cannon/machine gun;''
* ''references to approximate analogues by other nations and research trees.''

== External links ==
<!-- ''Paste links to sources and external resources, such as:''
* ''topic on the official game forum;''
* ''other literature.'' -->
* [[wikipedia:3-inch/50-caliber gun|[Wikipedia] 3-inch/50-caliber gun]]
* [http://www.navweaps.com/Weapons/WNUS_3-50_mk27-33-34.php <nowiki>[NavWeaps]</nowiki> 3"/50 (7.62 cm) Marks 27, 33 and 34]

{{USA naval cannons}}
{{Japan naval cannons}}

[[Category:Naval cannons]]